Address Julie's feedback

-decodeVectorMagnitude go back to Buffer
-correct documentation to use doc access methods for
	vector values and magnitude instead of get functions
- rename getVectorMagnitude to getMagnitude
- remove unnecessary yml tests

docs/reference/vectors/vector-functions.asciidoc

@@ -8,14 +8,14 @@ linearly scanned. Thus, expect the query time grow linearly
 with the number of matched documents. For this reason, we recommend
 to limit the number of matched documents with a `query` parameter.
 
-This is the list of available vector functions:
+This is the list of available vector functions and vector access methods:
 
 1. `cosineSimilarity` – calculates cosine similarity
 2. `dotProduct` – calculates dot product
 3. `l1norm` – calculates L^1^ distance
 4. `l2norm` - calculates L^2^ distance
-5. `getVectorValue` – returns a vector's value as an array of floats
-6. `getVectorMagnitude` – returns a vector's magnitude
+5. `doc[<field>].vectorValue` – returns a vector's value as an array of floats
+6. `doc[<field>].magnitude` – returns a vector's magnitude
 
 
 Let's create an index with a `dense_vector` mapping and index a couple
@@ -210,10 +210,10 @@ The recommended way to access dense vectors is through `cosineSimilarity`,
 `dotProduct`, `l1norm` or `l2norm` functions. But for custom use cases,
 you can access dense vectors's values directly through the following functions:
 
-- `float[] getVectorValue()` – returns a vector's value as an array of floats
+- `doc[<field>].vectorValue` – returns a vector's value as an array of floats
 
-- `float getVectorMagnitude()` – returns a vector's magnitude (available for
-vectors created in the version 7.5 or later).
+- `doc[<field>].magnitude` – returns a vector's magnitude as a float
+(available for vectors created in the version 7.5 or later).
 
 For example, the script below implements a cosine similarity using these
 two functions:
@@ -235,8 +235,8 @@ GET my-index-000001/_search
       },
       "script": {
         "source": """
-          float[] v = doc['my_dense_vector'].getVectorValue();
-          float vm = doc['my_dense_vector'].getVectorMagnitude();
+          float[] v = doc['my_dense_vector'].vectorValue;
+          float vm = doc['my_dense_vector'].magnitude;
           float dotProduct = 0;
           for (int i = 0; i < v.length; i++) {
             dotProduct += v[i] * params.queryVector[i];

x-pack/plugin/src/yamlRestTest/resources/rest-api-spec/test/vectors/20_dense_vector_special_cases.yml

@@ -189,55 +189,3 @@ setup:
 - match: {hits.hits.0._id: "1"}
 - match: {hits.hits.1._id: "2"}
 - match: {hits.hits.1._score: 0.0}
-
----
-"No sort, no aggs, no docvalue_fields are allowed":
-- do:
-    index:
-      refresh: true
-      index: test-index
-      id: 1
-      body:
-        my_dense_vector: [10, 10, 10]
-
-# sorting on dense_vector field is not supported
-- do:
-    catch: bad_request
-    search:
-      index: test-index
-      body:
-        query:
-          match_all: {}
-        sort:
-          my_dense_vector
-
-- match: { status: 400 }
-- match: { error.root_cause.0.reason: "Field [my_dense_vector] of type [dense_vector] doesn't support sort" }
-
-# aggs on dense_vector field are not supported
-- do:
-    catch: bad_request
-    search:
-      index: test-index
-      body:
-        aggs:
-          my_agg:
-            terms:
-              field: my_dense_vector
-
-- match: { status: 400 }
-- match: { error.root_cause.0.reason: "Field [my_dense_vector] of type [dense_vector] doesn't support docvalue_fields or aggregations" }
-
-
-  # docvalue_fields of dense_vector field are not supported
-- do:
-    catch: bad_request
-    search:
-      index: test-index
-      body:
-        query:
-          match_all: {}
-        docvalue_fields: ["my_dense_vector"]
-
-- match: { status: 400 }
-- match: { error.root_cause.0.reason: "Field [my_dense_vector] of type [dense_vector] doesn't support docvalue_fields or aggregations" }

x-pack/plugin/src/yamlRestTest/resources/rest-api-spec/test/vectors/30_dense_vector_script_access.yml

@@ -38,7 +38,7 @@
               script:
                 source: |
                   float s = 0;
-                  for (def el : doc['v'].getVectorValue()) {
+                  for (def el : doc['v'].vectorValue) {
                     s += el;
                   }
                   s;
@@ -51,7 +51,7 @@
   - match: { hits.hits.2._score: 3 }
 
 
-  # check getVectorMagnitude() API
+  # check getMagnitude() API
   - do:
       headers:
         Content-Type: application/json
@@ -61,7 +61,7 @@
             script_score:
               query: { "exists" : { "field" : "v" } }
               script:
-                source: "doc['v'].getVectorMagnitude()"
+                source: "doc['v'].magnitude"
 
   - match: { hits.hits.0._id: "3" }
   - gte: {hits.hits.0._score: 3.3166}
@@ -82,7 +82,7 @@
             script_score:
               query: { match_all: { } }
               script:
-                source: "doc['v'].getVectorValue()[0]"
+                source: "doc['v'].vectorValue[0]"
 
   - match: { status: 400 }
   - match: { error.root_cause.0.type: "script_exception" }
@@ -96,7 +96,7 @@
             script_score:
               query: { match_all: { } }
               script:
-                source: "doc['v'].getVectorMagnitude()"
+                source: "doc['v'].magnitude"
 
   - match: { status: 400 }
   - match: { error.root_cause.0.type: "script_exception" }
@@ -113,8 +113,8 @@
               query: { "exists": { "field": "v" } }
               script:
                 source: |
-                  float[] v = doc['v'].getVectorValue();
-                  float vm = doc['v'].getVectorMagnitude();
+                  float[] v = doc['v'].vectorValue;
+                  float vm = doc['v'].magnitude;
 
                   int closestPv = 0;
                   float maxCosSim = -1;

x-pack/plugin/vectors/src/main/java/org/elasticsearch/xpack/vectors/mapper/VectorEncoderDecoder.java

@@ -32,15 +32,11 @@ public static int denseVectorLength(Version indexVersion, BytesRef vectorBR) {
      */
     public static float decodeVectorMagnitude(Version indexVersion, BytesRef vectorBR) {
         assert indexVersion.onOrAfter(Version.V_7_5_0);
-        int offset = vectorBR.offset + vectorBR.length - INT_BYTES;
-        int intValue = ((vectorBR.bytes[offset] & 0xFF) << 24)   |
-            ((vectorBR.bytes[offset+1] & 0xFF) << 16) |
-            ((vectorBR.bytes[offset+2] & 0xFF) <<  8) |
-            (vectorBR.bytes[offset+3] & 0xFF);
-        return Float.intBitsToFloat(intValue);
+        ByteBuffer byteBuffer = ByteBuffer.wrap(vectorBR.bytes, vectorBR.offset, vectorBR.length);
+        return byteBuffer.getFloat(vectorBR.offset + vectorBR.length - 4);
     }
 
-    public static float getVectorMagnitude(Version indexVersion, BytesRef vectorBR) {
+    public static float getMagnitude(Version indexVersion, BytesRef vectorBR) {
         if (vectorBR == null) {
             throw new IllegalArgumentException("A document doesn't have a value for a vector field!");
         }

x-pack/plugin/vectors/src/main/java/org/elasticsearch/xpack/vectors/query/DenseVectorScriptDocValues.java

@@ -46,7 +46,7 @@ BytesRef getEncodedValue() {
     @Override
     public BytesRef get(int index) {
         throw new UnsupportedOperationException("accessing a vector field's value through 'get' or 'value' is not supported!" +
-            "Use 'getVectorValue' or 'getVectorMagnitude' instead!'");
+            "Use 'vectorValue' or 'magnitude' instead!'");
     }
 
     /**
@@ -60,8 +60,8 @@ public float[] getVectorValue() {
     /**
      * Get dense vector's magnitude
      */
-    public float getVectorMagnitude() {
-        return VectorEncoderDecoder.getVectorMagnitude(indexVersion, value);
+    public float getMagnitude() {
+        return VectorEncoderDecoder.getMagnitude(indexVersion, value);
     }
 
     @Override

x-pack/plugin/vectors/src/main/resources/org/elasticsearch/xpack/vectors/query/whitelist.txt

@@ -6,7 +6,7 @@
 #
 class org.elasticsearch.xpack.vectors.query.DenseVectorScriptDocValues {
     float[] getVectorValue()
-    float getVectorMagnitude()
+    float getMagnitude()
 }
 class org.elasticsearch.script.ScoreScript @no_import {
 }